GYPSUM

Organisation: Yara Finland

Time: 9/1/2010 – 10/1/2012

Description:

Novel measure of markedly reducing phosphorus leakage from fields into the Sea – Field treatment in most vulnerable coastal areas

Yara’s concrete commitment:
Yara is committing to treat 100 hectares of fields in South-Western Finland with its gypsum based product to markedly reduce phosphorus leakage. The commitment includes the gypsum-product, transportation and field spreading.

In addition Yara commits to draw a corporate Baltic Sea strategy during 2010.

Background
Phosphorus is an essential plant nutrient, plants need it to grow. The problem is that phosphorus, attached to soil particles, is transported from the fields through water run off into rivers, lakes and the Sea and thereby causes eutrophication. Farmers thus need specific tools to control soil erosion and thus phosphorus leakage.

Yara has developed a solution to stabilize soil particles on the field which in turn will reduce soil erosion by surface runoff and therefore trap phosphorus in the field. At the same time, adsorption of dissolved phosphorus on soil particles improves. As a consequence, phosphorus stays in the soil available for plants, instead of leaking into the waterways.

The solution is to spread a gypsum-based product on the field after harvest or before planting. Gypsum is calcium sulphate, which infiltrates with water into soil, improving the particle aggregation and dissolved phosphorus retention. Better soil structure means that the earth resists rain and melting snow better and therefore prevents erosion and phosphorus leakage. Gypsum also improves the plants ability to utilise soil phosphorus reserves.

Commitment based on research
The commitment is based on Yara’s ongoing research project TraP (2007-2011) that tests the use of gypsum based products to trap the phosphorus in the fields. The tests are done in laboratories and as full scale tests on the fields in cooperation with 15 farmers around Finland. The project is co-funded by Yara and Tekes and the total costs are over one million euros.

The midway results are very promising: erosion was reduced by 30-70%. Positive growth response and better nutrient uptake was found 2-3 years after the application.

Yara’s partners are:
Tekes (Finnish Funding Agency for Technology and Innovation), SYKE Finnish Environment Institute, MTT Agrifood Research Finland, TTS Work Efficiency Institute, Luode consulting, Water Protection Association of The River Vantaa and Helsinki region, VHSVY Funding and the Centre for Economic Development, Transport and the Environment for Southwest Finland.

The Centre for Economic Development, Transport and the Environment for Southwest Finland is committed to choose the hot spots of 100 hectares mostly in need of action as well as measure the impact of Yara’s commitment on soil erosion and P discharge.

The objective is to reduce phosphorus run-off caused by soil erosion, and dissolved phosphorus leaching from most vulnerable fields to waterways by application of the gypsum product in South-Western Finland. The agricultural area of South-Western Finland is risky because of its many rivers and its closeness to the Baltic Sea.

The commitment includes soil treatment by gypsum at a rate of 4 tn/ha. By one-time action of the soil amendment, immediate impact will be achieved according to the current results from the TraP-project. Meanwhile, farmers can continue their normal farming. It is anticipated that for optimal results of phosphorus load control, the treatment should be carried out each 3-4 year.